Three millionaire Upper East Siders must pay a combined $1 million in back taxes and penalties on money stashed in secret Swiss bank accounts, Manhattan prosecutors announced today.

The felony tax cheat convictions against Jules Robbins, 83, Ernest Vogliano, 80, and Federico Hernandez, 44, stem from a 2009 federal investigation into Swiss banking giant UBS, which turned over information about hidden offshore accounts under its management as part of a non-prosecution agreement.

“This office has long fought against the use of offshore accounts by tax cheats and other criminals,” said DA Cy Vance, noting that the recovered tax dollars would help projected city and state shortfalls in schools, hospitals and parks.

Prosecutors said Robbins, a watch distributor, has paid back $859,699; Vogliano must pay back $63,210; Hernandez must pay back $72,135.